(meteorobs) Observation July 27/28 2009

[Pierre Martin]

My Tuesday morning's session at Bootland Farm was a much better  
night!  Actually, it was great!  Not only did the sky completely clear  
up 3 hours earlier than forecasted, but the transparency was very good  
(about 4 out of 5).  It was also a much more comfortable night, with  
just a light breeze and no fog whatsoever.  Even the mosquitoes were  
nearly absent.  What a difference compared to the previous morning!   
Overhead, the Summer Milky Way was impressive with lots of structure,  
and stars as faint as 6.6 could be seen near the zenith.  Before  
setting up my chair, I gazed up a few more moments, and no fewer than  
3 nice meteors were seen within just seconds of each other.  I was now  
eager to start observing!

It turned out to be quite a productive session.  In three and a half  
hours of effective observing time, I recorded 91 meteors.  The second  
and third hours were the busiest ones, each with 29 meteors (for an  
average of about one meteor every two minutes).  There was a few  
instances of two meteors coming a split second apart, followed by a  
lull of no activity for a few minutes.  Not too surprisingly, the  
South Delta Aquarids was the dominant shower activity, with 26 members  
seen.  The Perseids were the second most conspicuous source with 13  
members.  Alpha Capricornids and antihelions were also present in  
small numbers.  No Pisces Austrinids were seen.

The most impressive meteor was a mag -2 antihelion that climbed a long  
30 degrees path, gradually flaring up in brightness, and changing from  
yellow to pure white.  It looked almost like an earthgrazing meteor!

Also had the company of Will Mercier who showed up with his 6 years  
old son, just after 12:30am - both came to enjoy the clear dark sky.

Pierre Martin
Ottawa, Ontario


DATE: July 27/28 2009
BEGIN: 04:05 UT (00:05 EDT) END: 08:00 UT (04:00 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -76 29' West; Lat: 45 23' North Elevation: 400 ft
Observing site: Bootland Farm, Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder, plotting
----------------------------------------------------------

OBSERVED SHOWERS:_______________________________radiant position
CAP (Alpha Capricornids)_________________________20:16 -11
ANT (Antihelion)_________________________________21:04 -15
SDA (South Delta Aquarids)_______________________22:28 -17
PAU (Pisces Austrinids)__________________________22:36 -31
PER (Perseids)___________________________________01:32 +53
SPO (sporadics)
----------------------------------------------------------

OBSERVING PERIODS: 0 = none seen; / = shower not observed

PERIOD(UT)____FIELD_______Teff____LM____SPO_ANT_CAP_SDA_PAU_PER

04:05-05:18___19:34 +05___1.00___6.55____9___1___4___6___0___2
05:18-06:26___21:05 +05___1.13___6.55___15___0___1___7___0___6
06:31-07:32___22:08 +06___1.01___6.55___11___2___2__11___0___3
07:32-08:00___22:59 +07___0.40___6.50____7___0___0___2___0___2

TOTALS:___________________3.54__________42___3___7__26___0__13  =  91


Note: The first column (Period UT) refers to observing periods broken  
down as close as possible to one hour of true observing, in Universal  
Time. The second column (Field) is the area in in the sky where I  
centered my field of view. The third column (TEFF) represents  
effective observing time (corrected for breaks or any time not spent  
looking at the sky), where 1.00 is exactly one hour. The column (LM)  
is the average naked eye limiting magnitude, determined by triangle  
star counts. All following columns indicate the number of meteors for  
each shower observed.
------------------------

MAGNITUDE DISTRIBUTIONS:

SHOWER
_____-2__-1___0__+1__+2__+3__+4__+5__+6______AVE

SPO___0___1___1___1___3___7__20___6___3_____+3.69
SDA___0___0___2___1__10___6___6___1___0_____+2.62
PER___0___0___2___3___2___2___3___1___0_____+2.31
CAP___0___0___0___3___1___0___2___1___0_____+2.57
ANT___1___0___0___0___1___0___1___0___0_____+1.33

Note: Magnitude -8 is comparable to a quarter moon, magnitude -4 with  
the planet Venus, magnitude -1 with the brightest star Sirius,  
magnitude +2 to +3 with most average naked eye stars and magnitude +6  
to +7 are the faintest stars the naked eye can see under typical dark  
conditions. A meteor of at least magnitude -3 is considered a fireball  
(IMO definition). The above table contains the magnitudes from all  
observed meteors, and the average (last column) for showers.
------------------------

SKY OBSCURED (FOV) (UT): None

------------------------

Dead time: 17.5 min (for breaks)

Breaks (UT): 4:26-27, 4:33-45, 6:26-31, 7:01 (30 sec), 7:34-38